let a = 1;
let b = 2;
class OY {
    constructor(name) {
        this.name = name;
    }
    show() {
        console.log(this.name);
    }
    static play() {
        console.log('static play');
    }
}

let aa = new OY('aa');
console.log(aa);
aa.show();

let bb = new OY('bb');
console.log(bb);
bb.show();

new Promise((resolve, reject) => {
    console.log(111);
    setTimeout(() => {
        resolve();
    }, 2000);
}).then(() => {
    console.log(222);
});

let lis = document.querySelectorAll('ul li');
lis.forEach((li, i) => {
    li.addEventListener('click', () => {
        console.log(i);
    });
});
